This invention relates to a method and apparatus for opening fiber bales using a carriage member movable along an aligned row of bales in a plurality of passes, and a head mounted to the carriage member for movement therewith, the head also being movable in a vertical direction to engage the top surfaces of the bales and to remove fiber therefrom as the carriage member moves along the bales.
Known apparatus of the foregoing type usually includes a rotating member mounted in head and having a plurality of teeth projecting radially therefrom in circumferential rows spaced along the axis of the rotating member, and a grate is provided to extend between the rows of teeth for compressing abutment with the top surface of the bales. Heretofore, the rotating member has always been mounted in the head for rotation about an axis that is perpendicular to the direction of movement of the head across the top surface of the bales, so that the projecting rows of teeth leave spaced furrows or grooves in the bale surface, with ridges of raised fiber therebetween where the bale surface is engaged and compressed by the grate. The formation of such grooves and ridges during one pass of the head over the bales can result, during subsequent passes of the head over the same bales, in the teeth removing less fiber because they pass through the grooves and/or the teeth removing large chunks or tufts of fiber from the raised ridges, all of which tends to cause significant variations in the size of the removed fiber tufts that can have adverse and undesirable consequences during the subsequent processing of such fiber. Some efforts have been made to avoid such adverse consequences, such as by periodically changing the position of the grate bars with respect to the bale as disclosed in Marx U.S. Pat. No. 4,281,437.
Also, in conventional bale opening equipment of the aforesaid type, the perpendicular relationship between the axis of the rotating member and the direction of movement along the aligned bales results in the head removing fiber from only one bale at a time. Frequently, the aligned bales consist of fibers of different types which must be subsequently blended, but no pre-blending of the removed fibers can be obtained from conventional bale opening equipment of the aforesaid type since fiber is removed from one bale at a time, in sequence, for delivery to further processing and blending equipment.
In most known bale opening equipment of the aforesaid type, the movement of the carriage and the head are controlled to move in a set pattern by which the carriage is moved back and forth along the aligned bales, and the head is moved vertically downwardly by a predetermined amount each time the head makes a new pass along the bales. However, because the different bales in the alignment or lay down may be different in terms of density, fiber type and other variables, the movement of the head across these different bales at a constant vertical height will often result in different quantities of fibers being removed from the individual bales, whereby such fibers will not be blended in correct proportions. In Trutzschler U.S. Pat. No. 4,297,766, a particular control system is disclosed in which the total quantity of each bale is determined, and a computer is used to compare such total quantity with the number of passes to be made by the head to determine the portion of the total which is to be removed during each pass of the head. The computer then controls the movement of the head to insure that it removes such determined portion. In both of the aforesaid known control systems, the head is moved across the bales at a constant vertical height during each pass, without compensation for any variations in the level of the top surface of a bale, and since the aforesaid variations in different bales will often result in the fibers in the bale reacting differently to the passage of teeth therethrough so as to create variations in the levels of the bales themselves, the failure to compensate for these variations can result in different, uncontrolled quantities of fiber being removed from the bales by the head, even to the extent, in some cases, of the head removing quantities of fibers that are sufficient to choke the head.
In the apparatus of the present invention, the aforesaid problems of known apparatus are significantly alleviated, and additional features are also provided to improve the operation of the apparatus of the present invention.